The Connection Object is a part of ADO.NET Data Provider and it is a unique session with the Data Source. In .Net Framework the Connection Object is Handling the part of physical communication between the application and the Data Source. Depends on the parameter specified in the Connection String , ADO.NET Connection Object connect to the specified Database and open a connection between the application and the Database . When the connection is established , SQL Commands may be executed, with the help of the Connection Object, to retrieve or manipulate data in the Database. Once the Database activity is over , Connection should be closed and release the resources .

In ADO.NET the type of the Connection is depend on what Database system you are working with. The following are the commonly using the connections in the ADO.NET

SqlConnection

OleDbConnection

OdbcConnection